recursive iteration through nested json for specif

2019-01-09 10:30发布

问题:

I'm trying to pull nested values from a json file. I want to print out each of the values for every "id" key. I think I'm close but can't figure out why the obj type changes from a dict to a list, and then why I'm unable to parse that list. Here is a link to the json I'm working with: http://hastebin.com/ratevimixa.tex

and here is my current code:

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import json

json_data = open('JubJubProductions.json', 'r+')
jdata = json.loads(json_data.read().decode("utf-8"))

def recursion(dict):

    for key, value in dict.items():

        if type(value) == type(dict):
            if key != "paging":
                for key, value in value.items():
                    if isinstance (value,list):
                        print key
                        # place where I need to enter list comprehension?
                if type(value) == type(dict):
                    if key == "id":
                        print " id found " + value
                    if key != "id":
                        print key + " 1st level"
                if key == "id":
                    print key
        else:
            if key == "id":
                print "id found " + value       
if __name__ == '__main__':
    recursion(jdata)

-------------------------------------------------------------------------------------------update

This is now what I'm working with and it'll return a single id value, but not all of them:

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import json

json_data = open('jubjubProductions', 'r+')
jdata = json.loads(json_data.read().decode("utf-8"))

def id_generator(d):
    for k, v in d.items():
        if k == "id":
            yield v
        elif isinstance(v, dict):
            for id_val in id_generator(v):
                yield id_val

if __name__ == '__main__':
    for _ in id_generator(jdata):
        print (_)

回答1:

def id_generator(dict_var):
      for k, v in dict_var.items():
            if k == "id":
                 yield v
            elif isinstance(v, dict):
                 for id_val in id_generator(v):
                       yield id_val

This will create an iterator which will yield every value on any level under key "id". Example usage (printing all of those values):

for _ in id_generator(some_json_dict):
     print(_)


回答2:

The JSON might contain a list of objects, which needs to be searched:

Python 2.7 version:

def item_generator(json_input, lookup_key):
    if isinstance(json_input, dict):
        for k, v in json_input.iteritems():
            if k == lookup_key:
                yield v
            else:
                for child_val in item_generator(v, lookup_key):
                    yield child_val
    elif isinstance(json_input, list):
        for item in json_input:
            for item_val in item_generator(item, lookup_key):
                yield item_val

Python 3.x version:

def item_generator(json_input, lookup_key):
    if isinstance(json_input, dict):
        for k, v in json_input.items():
            if k == lookup_key:
                yield v
            else:
                yield from item_generator(v, lookup_key)
    elif isinstance(json_input, list):
        for item in json_input:
            yield from item_generator(item, lookup_key)